e85 switch
Graphs all look good, no detonation... Im running ARP studs and cometic gaskets ( 0.040 ) and 8:1 compression... was at 20 lbs of boost when I blew the last hose...
BOTTOM end is fine !! I really dont want to switch blocks to steel... Is the problem ? ... the aluminum block threads arent strong enough to keep the studs planted ? Would it help to " time cert" new 1/2 threads into the aluminum block and then put studs into that ?
or would that be a waste of time ?
the rpm graph looks smooth... no dips like it would be detonating... but I have serious coolant pressure... oil looks fine on the dipstick so I dont think the block is cracked. the black line is my TPS... ( you can see when the radiator blows , it hits my windshield and scared me into diping my TPS when I was in top gear half way through ) My timing is in the RED... is that too much ? AFR is purple/pink. MAP is blue RPM is neon green
So can I just send the heads out to get o-ringed somewhere ? should I "time cert " the block threads for a better hold ? or drain the coolant, jack up the car on one side at a time and pour hard block in ??? whats my best bet ??
You need to pull the heads and install new gaskets if you pressurized the radiator. They never seal the same after they lift. Can you run the LS9 OEM gasket with your bore? What did you torque the HG to? Which cometic gasket? Did you surface the heads/block to the suggested RA finish?
E85 doesn’t register knock/detonation like pump and race gas. It jumps straight into pre-ignition and breaks things. You get little to no warning. Very similar to methanol tunes.
25* is *generally* a lot of timing for 20lbs… For comparison I run 12-13* on E85 intercooled at 20lbs. My alum 5.3 held the heads down just fine with china head studs at 26+lbs…Until I bumped the timing from 15* to 17*. Which blew the HG and pressurized the rad just like you. The alum threads are not weak/neither is the block. Always start low on timing… like 9-10*. Then bump a degree and check the plugs.
Last edited by Forcefed86; Jan 25, 2016 at 09:55 AM.
Im running meth injection... here is what my temperature graph looks like.
Cam is the street lingfelter blower cam.
It is the stainless multilayer cometic gaskets ... 0.040 thickenss, new block and heads were resurfaced before bolted them down .. I think at 80 flbls. ( been about 5 years ago)
car is only 2500 lbs... so its not alot of weight to push either....
I was running pump gas fine and when I switched blowers to this f3r and hit 15 lbs of boost at 4000 rpm, decided to switch to e85. The boost in the graph was only at 63 % throttle... so Im not quite where its going to be yet and not sure what i can do to make it where I can get more runs out of it before rebuilding ....
I can switch gaskets to whatever ... just not sure if o-ringing should be an option ? I read that there is some kind of ISKY tool that will oring the block ? and then run a copper gasket ? is that hard ? or a good option ?
I didnt even pull the plugs yet...DOH...
it helps control fire ring damage caused by detonation but if it is severe enough it will still let the gasket go. I went probably 3yrs after I o-ringed a 302 Block until one day I over ran the MAF tune past 70lb/min & it let go on the big end. Even with the o-rings it still ended up spitting coolant out from between the block & head.
If the head is lifting enough, o-ringed doesn't stop it entirely.
Add: That happened running 114 Octane... But I was already pushing ~1725 EGT on the big end...
Last edited by gtfoxy; Jan 25, 2016 at 10:13 AM.
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Was the block/head surfaced to 50RA or finer? Or just “surfaced”? If not that’s most likely an issue as well. My cometics were always picky, nothing like the LS9 gasket. If you’re bore isn’t too large to run an LS9 gasket I’d highly suggest it. I torqued my std diameter ARP studs to 85ftlb. I’ve run 30+lbs without head sealing issues. O-rings work great with copper gaskets. Just a matter of time money, that’s up to you. I think an LS9 gasket with a proper tune should be more than fine at 20ish lbs.
8:1 Compression is super low. My 8.6:1 5.3 liked about 17*. Where my 10:1 stuff doesn’t like more than 12-14* @ 25ish lbs. This was also not a supercharged setup and was using a neg. overlap @ .050 cam. I know a lot of times the SC setups run a high duration cam where you’re bleeding off a ton of cyl pressure, so you can get away with much higher timing numbers… Do you have the actual cam card with the specs on it for us?
Learning to read plugs and doing it often is the best tuning method for any alky fueled car. Start low on timing and work your way up slowly watching plugs. If you know how to read them, it’s very hard to hurt the engine tuning this way. Most (including me) don’t do it nearly as often as they should.
Tough to answer your question without getting long winded, how much fluid do you inject? 100% meth? The small amounts of meth most inject don’t have a large effect on IAT’s like the companies want you to believe. They help most in the CC by upping octane and pulling heat there. I prefer to know my actual charge temps to tune by. My IAT sensor is just after the IC. I spray my meth at the TB. This way I get my actual charge temps post IC that aren’t skewed by false aux injection saturating the sensor. If you’re spraying pre-compressor you don’t have a lot of choice. Just put the IAT sensor as far away as possible. Are you intercooled as well?
There was a guy posted not long ago that was running 24* of timing but IDR the set-up entirely but IIRC it was a turbo.
its the snow kit .. one nozzle.. i will be adding another nozzle... no intercooler.
Last edited by monsterchevylizzard; Jan 25, 2016 at 01:40 PM.
Its simply too much timing. E85 will not show knock- it will juts be "all good" on the tune and sling a rod!
Move the Meth nozzle post IAT, put some head gaskets on there and RIP it. No way you need an O ring with 20 psi on any turbo with a good tune. T66 or single 101, it should be fine. Dont over complicate the repair.
Surface finish on the heads and block are important. If you can see the machine marks, its too coarse.
I thinks it's best not to touch the block. GM does a great job there.
I actually had my heads lapped smooth.
Then ran the LS9 gasket.
Hearing that E85 doesn't show detonation is a first for me.
Given that you are doing long pulls, much harder on parts than us 1/4 milers, I agree that you need to cut the timing back and try again. Power goes up when you get it right.
Timing = power is only correct at the sweet spot.
Sounds like a fun ride!










